Short answer
HubSpot's KB: templates outside WhatsApp's categories are likely rejected and can't be used. You can insert variables to personalize in HubSpot, and some sections like headers can include media. From April 1, 2025, Meta paused WhatsApp marketing template messages to US numbers; utility and authentication messages continue. HubSpot recommends the updated template experience.
1. WhatsApp settings
WhatsApp settings in my demo portal.

2. Consent
WhatsApp needs opt-in. See WhatsApp in HubSpot.